Realm Therapeutics PLC Realm: Preclinical Data on PR022 Published

TIDMRLM

Realm Therapeutics PLC

21 November 2017

Realm Therapeutics Announces Publication of Positive Preclinical Data on PR022 in the Treatment of Atopic Dermatitis

In Vivo and In Vitro Data Demonstrate Reduced Itch and Inflammation

Progressing to Phase 2 trial in coming weeks

MALVERN, PA, November 21 2017 - Realm Therapeutics plc (AIM:RLM), a clinical stage biopharmaceutical company focused on leveraging its proprietary immunomodulatory technology, today announced the publication of preclinical data demonstrating that PR022, the Company's proprietary topical gel formulation of high concentration hypochlorous acid (HOCl), results in a significant reduction of itch and inflammation associated with atopic dermatitis (AD) in vivo and in vitro. The article, "Hypochlorous acid is anti-pruritic and anti-inflammatory in a mouse model of atopic dermatitis," was published online in Clinical & Experimental Allergy.

Researchers evaluated the effect of topical administration of HOCl hydrogel (0.05%) on AD-like lesions in a widely - accepted NC/Nga mouse model, as well as the in vitro effects of HOCl on dorsal root ganglia neurons and mouse bone marrow derived dendritic cells (mBMDC). Treatment with HOCl reduced the secretion of inflammatory cytokines in affected skin tissue from NC/Nga mice, including IL-4, IL-13, and TARC; induced a dose-dependent reduction of IL-12 in mBMDC, a key cytokine associated with Th1 dominance in chronic skin lesions; and reduced lesions and scratching behavior, including reduction of pruritogens IL-31 and TSLP, to a similar extent as the positive control, 0.1% betamethasone dipropionate ointment, a high potency steroid.

"These data reinforce that PR022 has the potential to offer patients suffering from atopic dermatitis an alternative treatment to steroids, which have significant side effects," said Alex Martin, Chief Executive Officer of Realm. "Treatment with PR022 prevented the development of AD-like lesions, reduced existing lesions and associated scratching, and reduced the inflammatory response, including cytokine production. AD is a prevalent and burdensome disease and we are extremely pleased to be advancing PR022 into Phase 2 studies in the coming weeks."

About Atopic Dermatitis (AD)

AD, a serious form of eczema, is a chronic, relapsing, inflammatory disease characterised by itchy, inflamed skin, which poses a significant burden on patients' quality of life and on the overall health care system. Patients with AD have impaired function of their skin barrier, and this, combined with skin damage as a result of the intense itching and scratching associated with the disease, makes them at risk for secondary infections due to colonisation with pathogenic bacteria (particularly Staphylococcus aureus) and changes in the skin microbiome. AD affects up to 20% of children and up to 3% of adults and prevalence numbers continue to increase.

About Realm Therapeutics

Realm Therapeutics is a clinical-stage biopharmaceutical company focused on developing novel immunomodulatory therapies to protect and improve the lives of adults and children. The Company has initiated drug development programs, based on its proprietary hypochlorous acid technology at high concentrations. The Company believes its formulations have novel immunomodulatory activity with potential application for the treatment of diseases in a number of therapeutic areas, including Dermatology and Ophthalmology.

Forward Looking Statements

Certain statements made in this announcement are forward-looking statements. These forward-looking statements are not historical facts but rather are based on the Company's current expectations, estimates, and projections about its industry; its beliefs; and assumptions. Words such as 'anticipates,' 'expects,' 'intends,' 'plans,' 'believes,' 'seeks,' 'estimates,' and similar expressions are intended to identify forward-looking statements. These statements are not guarantees of future performance and are subject to known and unknown risks, uncertainties, and other factors, some of which are beyond the Company's control, are difficult to predict, and could cause actual results to differ materially from those expressed or forecasted in the forward-looking statements. The Company cautions shareholders and prospective shareholders not to place undue reliance on these forward-looking statements, which reflect the view of the Company only as of the date of this announcement. The forward-looking statements made in this announcement relate only to events as of the date on which the statements are made. The Company will not undertake any obligation to release publicly any revisions or updates to these forward-looking statements to reflect events, circumstances, or unanticipated events occurring after the date of this announcement except as required by law or by any appropriate regulatory authority.

Contact:

Realm Therapeutics plc

Alex Martin, Chief Executive Officer

Marella Thorell, Chief Financial Officer and Chief Operating Officer

+44 (0) 20 3727 1000

Argot Partners

Stephanie Marks

+1 212 600 1902

FTI Consulting

Simon Conway / Mo Noonan

+44 (0) 20 3727 1000

N+1 Singer (Nominated Adviser and Broker) Aubrey Powell / Lauren Kettle